Don't know of anybody who used LL-2733, some have gone for a different manufacturer, most have used LL-1694 either in series or common mode. most have gone for LCLC and some for CLCLC, I've not seen other flavors in the unregulated supplies. Just some bleeders to set the desired voltage.
Hope that help.
i recently built a clclc psu with high inductance amorphous core chocks (5H, 150mA, 75 ohm) and to my ears it sounds much better than using the low-inductive filament chocks which i tested before.
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Hello,
i did buy both lundahls but did not yet constructing the dac.
i wanted to use the high inductance for the choke input position.
but when you are using more than 1 board you will need a bigger current rating. Using a higher induction like 5, 10 or even 15 H you will get a huge voltage drop if you use it right after the recifier. 75 ohm is a lot compared to the 1, 2, 4 ohm from the higher current models.i think with a single board the second choke could be a 10 H one.
not sure if a big Henry power supply and a single board will be better than a lower inductance supply with 4 boards.
greetings, eduard
i did buy both lundahls but did not yet constructing the dac.
i wanted to use the high inductance for the choke input position.
but when you are using more than 1 board you will need a bigger current rating. Using a higher induction like 5, 10 or even 15 H you will get a huge voltage drop if you use it right after the recifier. 75 ohm is a lot compared to the 1, 2, 4 ohm from the higher current models.i think with a single board the second choke could be a 10 H one.
not sure if a big Henry power supply and a single board will be better than a lower inductance supply with 4 boards.
greetings, eduard
i ordered them from "ae europe" ( AE transformatoren specialist in transformatoren voor de elektrotechnische industrie)
i am using them in the psu with a single deck; the total current consumption of the dac is 112mA, so the 150mA chocks do a really good job. they stay so cold that i think they can probably be loaded with much higher than 150mA as they are specified.
i use a 2x15v main transformer (120VA) with 2x rectifiers; after the first cap (470uf) i measure 21v and at the last cap i still have 11.5v . so just approx. 4.5v voltage drop over the chocks (i was expecting 8-9v !
)regards
Thx stijn
I have been reading a lot about choke filtering psu this weekend, and are leaning forward to try the CLCLC choke setup as Supersurfer shows in post "1766".
But a few things are not clear to me yet. Since my trafo is 250va- 2x15v the dc voltage after rectifier will be around 21vdc. I guess it's best to get a 12v transformer so there is no need for regulation ? Or can I solve it with some resistor(s) after the last caps? If so, how do I calculate the value on the resistor?
i ordered them from "ae europe" ( AE transformatoren specialist in transformatoren voor de elektrotechnische industrie)
i am using them in the psu with a single deck; the total current consumption of the dac is 112mA, so the 150mA chocks do a really good job. they stay so cold that i think they can probably be loaded with much higher than 150mA as they are specified.
i use a 2x15v main transformer (120VA) with 2x rectifiers; after the first cap (470uf) i measure 21v and at the last cap i still have 11.5v . so just approx. 4.5v voltage drop over the chocks (i was expecting 8-9v !
regards
Would you mind telling what you were charged and how much those lovely things weigh?
That has to be the ultimate choke for a 4P1L line stage supply.
Thanks,
i bought the chocks many years ago for a 300b tube amp psu and do not honestly remember the exact price anymore; maybe about 70 euros each (?); ... they are bigger than the lundahl's filament chocks but not very much!. just drop the ae-europe an email asking for the specs/price and they reply very quickly! they do all kind of custom made audio transformers and deliver very good quality. manufacturing time is(was) about 4 weeks.
sorry, not being able to answer your questions exactly .
my worry was if the high resistance of the chocks may limit the current somehow and as the result the dynamics will be decreased for the dddac application. but surprising the psu is even more dynamic and has a better controlling than with the filament chocks. at least this is my feeling
! furthermore, i have the impression that by using the higher inductive chocks , the size (wattage) of the main transformer become less critical. i have tested this psu with the dddac standard small psu transformer without having the impression that the sound quality is less impressive ;-)maybe someone else here can try that as well and comment the results. would be interessting for me too! ;-)
regards
Something to bare in mind is that once the DDDAC is connected you'll get another 1 to 2 voltage drop due to the load, depending on nr of boards and shunts etc. I know people who have used 12V trafo's ended up with +/-10Vdc. I personally use a 18V trafo with a 75R bleeder which gives me 12.5Vdc with LCLC configuration. So somewhere between a 15-18V trafo seems to be the sweetspot, but this also depends on chokes used etc.. So to be on the safe side I'd aim slightly to high and dial it in with a bleeder.
Or unwind the trafo, which is surprisingly easy.
But I'm sure Eduard will know better, it's his area of expertise.
OK, then I just go for the15v trafo I already have. If I drop the caps after the rectifier and end up with LCLC configuration and a bleeder resistor around 50R maybe things will be close to the 12v target.
I have 4 boards, but no shunts. Where can I buy the bleeder resistor ? Is there a bleeder that is consider to be the best or ?
I have 4 boards, but no shunts. Where can I buy the bleeder resistor ? Is there a bleeder that is consider to be the best or ?
Hi,
My setup is cap input, not choke input.
I have used small caps with choke input in tube amps a lot. The sound ma be to your liking, it is in between the choke and cap input, depending on the value it will shift to one of the two.
Try 0,47uf and build up from that while listening. More cap will give you more bass, use it to balance the sound.
Btw. For your tube amps: direct AC powered filaments for the 300B sounds absolutely most dynamic and detailed! Balance the AC with a balancing pot and you will not have any trouble with hum.
I build a 300B tube amp with 12SN7 driver-input tubes all AC heated and they are really silent! More silent than my own directly heated DC heated amps.......
My setup is cap input, not choke input.
I have used small caps with choke input in tube amps a lot. The sound ma be to your liking, it is in between the choke and cap input, depending on the value it will shift to one of the two.
Try 0,47uf and build up from that while listening. More cap will give you more bass, use it to balance the sound.
Btw. For your tube amps: direct AC powered filaments for the 300B sounds absolutely most dynamic and detailed! Balance the AC with a balancing pot and you will not have any trouble with hum.
I build a 300B tube amp with 12SN7 driver-input tubes all AC heated and they are really silent! More silent than my own directly heated DC heated amps.......
Rod Coleman suggests using a 1 uF cap after rectifiers as a filter for rectifier noise. He is concerned with supplying power to valves but the concept has just aqs much merit for semis. You can use more capacitance if you need more voltage. I would want to keep it below 5 uF, just a number plucked from the air of instinct.
The best thing about the small input cap is hat it gives you some adjustability. Along with the bleeder you can finagle until you get what you want.
Have just discovered that the first 2 boards I bought marked 24/192 have the 1k data delay resistor fitted whereas the later 2 boards I added have 3x 100r resistors.
What is:
A)the likely effect on SQ when 2 of each are mixed?
B) when the 1k resistor is used with the later clock delay circuit?
Thanks
What is:
A)the likely effect on SQ when 2 of each are mixed?
B) when the 1k resistor is used with the later clock delay circuit?
Thanks
Cool, thanks. Just reading Rod's recent thread here on exactly that
Not ideal! It means that 2 of your decks are getting a music data signal that is delayed a different amount to the other 2, so you'll have a less accurate output I would have thought. Certainly you want them the same in all 4 boards. 100r if you have the extra clock delay circuit or 1k if not